The 301st prohibition is that we are forbidden from gossiping.
The source of this commandment is G‑d's statement (exalted be He),1 "Do not go around as a gossiper among your people."
Our Sages2 explained, "Do not speak softly to one and harshly to another. Another explanation: Do not act like a traveling salesman by traveling around carrying words."3
Sifra.
The Hebrew word for gossiper is "rachil." The first explanation of the Sifra finds an allusion to the word "rach", meaning "soft." In the context of the previous verse, which speaks of how a judge should treat his litigants, this means not to speak softly to one and harshly to another. The second explanation is based on the word, "rocheil," which means a traveling salesman.
Ketuvot 46a..
Literally, "bad name." "Motzi shem ra" refers to false gossip. "Lashon ha'ra" (literally, "evil tongue") refers to gossip which is true, but negative. "R'chilus" (translated here as "gossiping") refers to any gossip. See Hilchos De'os 7:2.
